src/usr/lib/xymon/client/ext/dnsq: use rdstring instead of rdatastr
requested to merge larskoll-guest/hobbit-plugins:kollstedt/fix_dnsq_rdstring_instead_rdatastr into master
Fix deprecation warning in dnsq status message. Should work with Net::DNS >= 1.01.
Replace !4 (closed) since it shows necessary rebase, but rebase doesn't work.